As 390 g of hot milk cools in a mug, it transfers 30,000 J of heat to the environment. What is the temperature change of the milk? The specific heat of milk is 3.9 J/g·°C. Show your work.

Pretty sure you'd solve this faster with little multiplication and division than writing the question here. :) Just be careful with your units, you've probably reached the correct one when you end up with the units of degrees Celsius.